Solar radiation use efficiency by soybean under field conditions in the Amazon region

Pesquisa Agropecuária Brasileira

Paulo Jorge De Oliveira Ponte De Souza²  Aristides Ribeiro¹  Edson José Paulino Da Rocha¹  José Renato Bouça Farias¹  Renata Silva Loureiro¹  Carlos Capela Bispo¹  Leila Sampaio² 

[1] ,Universidade Federal Rural da AmazôniaBelém PA ,Brazil

关键词: Glycine max;    Amazon region;    leaf area index;    radiation interception;    Glycine max;    região Amazônica;    índice de área foliar;    interceptação da radiação;   

DOI  :  10.1590/S0100-204X2009001000001

来源: SciELO

【 摘 要 】

The objective of this work was to evaluate the efficiency of soybean (Glycine max) in intercepting and using solar radiation under natural field conditions, in the Amazon region, Brazil. The meteorological data and the values of soybean growth and leaf area were obtained from an agrometeorological experiment carried out in Paragominas, Pará state, during 2007 and 2008. The radiation use efficiency (RUE) was obtained from the ratio between the above-ground biomass production and the intercepted photosynthetically active radiation (PAR) accumulated to 99 and 95 days after sowing, in 2007 and 2008, respectively. Climatic conditions during the experiment were very distinct, with reduction in rainfall in 2007, which began during the soybean mid-cycle, due to the El Niño phenomenon. An important reduction in the leaf area index and biomass production was observed during 2007. Under natural field conditions in the Amazon region, the values of RUE were 1.46 and 1.99 g MJ-1 PAR in the 2007 and 2008 experiments, respectively. The probable reason for the differences found between these years might be associated to the water restriction in 2007 coupled with the higher air temperature and vapor pressure deficit, and also to the increase in the fraction of diffuse radiation that reached the land surface in 2008.

【 授权许可】

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